Tsuga canadensis

An iconic tree of gorges, growing tall in the shaded north-facing slopes and capable of living hundreds of years. Also found in cool forests and can form monocultures where the ground is so shaded that the herb layer is very sparse. With climate change, wooly adelgids have been able to survive our warmer winters, thus posing a serious threat to all hemlocks. (It was removed from "recommended for gardening" for that reason.)